func enforceRetentionBypassForDelete(ctx context.Context, r *http.Request, bucket string, object ObjectToDelete, oi ObjectInfo, gerr error) error {
	if gerr != nil { // error from GetObjectInfo
		if _, ok := gerr.(MethodNotAllowed); ok {
			// This happens usually for a delete marker
			if oi.DeleteMarker || !oi.VersionPurgeStatus.Empty() {
				// Delete marker should be present and valid.

		t.Fatal("Unlock timed out, which should not happen")
	case <-timer.C:
	}
}

// Borrowed from mutex_test.go
func HammerMutex(m *DRWMutex, loops int, cdone chan bool) {
	for i := 0; i < loops; i++ {
		m.Lock(id, source)
		m.Unlock(context.Background())
	}
	cdone <- true
}

// Borrowed from mutex_test.go
func TestMutex(t *testing.T) {
	loops := 200
	if testing.Short() {
		loops = 5
	}

var ErrInvalidChecksum = errors.New("invalid checksum")

// SetExpectedMin set expected minimum data expected from reader
func (r *Reader) SetExpectedMin(expectedMin int64) {
	r.expectedMin = expectedMin
}

// SetExpectedMax set expected max data expected from reader
func (r *Reader) SetExpectedMax(expectedMax int64) {
	r.expectedMax = expectedMax
}

	}

	// Delete remote object from warm-tier
	err := deleteObjectFromRemoteTier(ctx, oi.TransitionedObject.Name, oi.TransitionedObject.VersionID, oi.TransitionedObject.Tier)
	if err == nil {
		// Skip adding free version since we successfully deleted the
		// remote object
		opts.SkipFreeVersion = true
	} else {
		transitionLogIf(ctx, err)
	}

	// Now, delete object from hot-tier namespace

)

const (
	psqlTableExists          = `SELECT 1 FROM %s;`
	psqlCreateNamespaceTable = `CREATE TABLE %s (key VARCHAR PRIMARY KEY, value JSONB);`
	psqlCreateAccessTable    = `CREATE TABLE %s (event_time TIMESTAMP WITH TIME ZONE NOT NULL, event_data JSONB);`

	psqlUpdateRow = `INSERT INTO %s (key, value) VALUES ($1, $2) ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value;`
	psqlDeleteRow = `DELETE FROM %s WHERE key = $1;`

	if !compareSignatureV2(gotSignature, expectedSignature) {
		return ErrSignatureDoesNotMatch
	}

	r.Form.Del(xhttp.Expires)

	return ErrNone
}

func getReqAccessKeyV2(r *http.Request) (auth.Credentials, bool, APIErrorCode) {
	if accessKey := r.Form.Get(xhttp.AmzAccessKeyID); accessKey != "" {
		return checkKeyValid(r, accessKey)
	}

	if err != nil {
		return cred, "", "", time.Time{}, ErrMalformedDate
	}

	// Query string.
	queryStr := req.Form.Encode()

	// Get canonical request.
	canonicalRequest := getCanonicalRequest(extractedSignedHeaders, payload, queryStr, req.URL.Path, req.Method)

	// Get string to sign from canonical request.
	stringToSign := getStringToSign(canonicalRequest, date, signV4Values.Credential.getScope())

		h.wg.Add(1)
		defer h.wg.Done()

	}
	h.logChMu.RUnlock()

	if logCh == nil {
		return
	}

	// Create a routine which sends json logs received
	// from an internal channel.
	for entry := range logCh {
		h.logEntry(entry)
	}
}

func (h *Target) logEntry(entry interface{}) {
	atomic.AddInt64(&h.totalMessages, 1)
	if err := h.send(entry); err != nil {

// as mandated by RFC 3986 Section 6.2.3.
func removeEmptyPort(host string) string {
	if hasPort(host) {
		return strings.TrimSuffix(host, ":")
	}
	return host
}

// Copied from http.NewRequest but implemented to ensure we reuse `url.URL` instance.
func (c *Client) newRequest(ctx context.Context, u url.URL, body io.Reader) (*http.Request, error) {
	rc, ok := body.(io.ReadCloser)
	if !ok && body != nil {

// generates CopyObjectResponse from etag and lastModified time.
func generateCopyObjectResponse(etag string, lastModified time.Time) CopyObjectResponse {
	return CopyObjectResponse{
		ETag:         "\"" + etag + "\"",
		LastModified: amztime.ISO8601Format(lastModified.UTC()),
	}
}

// generates CopyObjectPartResponse from etag and lastModified time.